2
$\begingroup$

From this paper, I see that the fidelity of single qubit gate after using dynamical decoupling only reach around 0.85 while I normally saw experiment papers state their fidelity can reach around 0.99 to be a good result. So my question is, does 0.85 a good fidelity with the method of dynamical decoupling, if so, I think this fidelity is a little bit low? enter image description here

$\endgroup$

1 Answer 1

4
$\begingroup$

I think you're confusing this with reported numbers for average gate fidelities.

The authors are estimating the fidelity of the time-evolved state with the initial state $|\psi\rangle$. If you prepare a state $|\psi\rangle$, and not do anything, it will (among other things) decohere such that the fidelity of the time-evolved state with $|\psi\rangle$ decreases with time. In particular, it is not surprising that you don't find great fidelities if you wait long enough. The purpose of dynamical decoupling is to counter-act this, at least to some extent, and that's what's presented in this plot.

The thing is that DD is an error mitigation technique, so it does not need fully-fledged error correction to work. For certain NISQ applications, this might be enough. Besides, this can be combined with QEC, and less noise usually means less overhead by QEC!

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.